Helicon double-layer thruster

The Helicon Double Layer Thruster is a prototype spacecraft propulsion engine. It was created by Australian scientist Dr. Christine Charles, based on a technology invented by Professor Rod Boswell, both of the Australian National University.

The design has been verified by the ESA, who is participating in its development.

Theory of operation

Gas is injected into a tubular chamber with one open end. Radio frequency energy excites the gas, ionizing it to produce plasma. Solenoids create a magnetic field that is nearly constant in the source tube, but expands rapidly out the end of the tube. The high density plasma is restricted from exiting the source tube by the current free electric double layer, which is a non-linear plasma effect that provides both restriction and a strong electric field gradient to accelerate the plasma, thereby creating thrust.

The Helicon Double Layer Thruster has some advantages over existing ion thruster designs; first, the effect is created by the plasma density and magnetic field geometry, and doesn't require the acceleration grids needed in current designs. Secondly, a neutralizer isn't needed, since there are equal numbers of electrons and positive ions emitted.

Applications

The primary application for this thruster design is intended for satellite station keeping, where a typical design could provide a fifty year life span, or a saving of 1000 lbs of launch weight for large satellites. This type of thruster could also significantly reduce the length of interplanetary space trips.[1]

Sources

• ANU page
• ESA: ESA Accelerates Towards A New Space Thruster
• Dr. Boswell and Charles' patent
• Plasma thruster tested for Mars mission